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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to you under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.calcite.interpreter;
import org.apache.calcite.DataContext;
import org.apache.calcite.linq4j.AbstractEnumerable;
import org.apache.calcite.linq4j.Enumerable;
import org.apache.calcite.linq4j.Enumerator;
import org.apache.calcite.linq4j.Linq4j;
import org.apache.calcite.linq4j.Ord;
import org.apache.calcite.linq4j.TransformedEnumerator;
import org.apache.calcite.plan.RelOptCluster;
import org.apache.calcite.plan.hep.HepPlanner;
import org.apache.calcite.plan.hep.HepProgram;
import org.apache.calcite.plan.hep.HepProgramBuilder;
import org.apache.calcite.prepare.CalcitePrepareImpl;
import org.apache.calcite.rel.RelNode;
import org.apache.calcite.rel.RelVisitor;
import org.apache.calcite.rel.rules.CalcSplitRule;
import org.apache.calcite.rel.rules.FilterTableScanRule;
import org.apache.calcite.rel.rules.ProjectTableScanRule;
import org.apache.calcite.rel.type.RelDataType;
import org.apache.calcite.rel.type.RelDataTypeFactory;
import org.apache.calcite.rex.RexCall;
import org.apache.calcite.rex.RexInputRef;
import org.apache.calcite.rex.RexLiteral;
import org.apache.calcite.rex.RexNode;
import org.apache.calcite.sql.fun.SqlStdOperatorTable;
import org.apache.calcite.util.Pair;
import org.apache.calcite.util.ReflectUtil;
import org.apache.calcite.util.ReflectiveVisitDispatcher;
import org.apache.calcite.util.ReflectiveVisitor;
import org.apache.calcite.util.Util;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import com.google.common.collect.LinkedHashMultimap;
import com.google.common.collect.Lists;
import com.google.common.collect.Multimap;
import java.math.BigDecimal;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Objects;
/**
* Interpreter.
*
* Contains the context for interpreting relational expressions. In
* particular it holds working state while the data flow graph is being
* assembled.
*/
public class Interpreter extends AbstractEnumerable
implements AutoCloseable {
private final Map nodes;
private final DataContext dataContext;
private final RelNode rootRel;
/** Creates an Interpreter. */
public Interpreter(DataContext dataContext, RelNode rootRel) {
this.dataContext = Objects.requireNonNull(dataContext);
final RelNode rel = optimize(rootRel);
final CompilerImpl compiler =
new Nodes.CoreCompiler(this, rootRel.getCluster());
Pair> pair = compiler.visitRoot(rel);
this.rootRel = pair.left;
this.nodes = ImmutableMap.copyOf(pair.right);
}
private RelNode optimize(RelNode rootRel) {
final HepProgram hepProgram = new HepProgramBuilder()
.addRuleInstance(CalcSplitRule.INSTANCE)
.addRuleInstance(FilterTableScanRule.INSTANCE)
.addRuleInstance(FilterTableScanRule.INTERPRETER)
.addRuleInstance(ProjectTableScanRule.INSTANCE)
.addRuleInstance(ProjectTableScanRule.INTERPRETER).build();
final HepPlanner planner = new HepPlanner(hepProgram);
planner.setRoot(rootRel);
rootRel = planner.findBestExp();
return rootRel;
}
public Enumerator enumerator() {
start();
final NodeInfo nodeInfo = nodes.get(rootRel);
final Enumerator rows;
if (nodeInfo.rowEnumerable != null) {
rows = nodeInfo.rowEnumerable.enumerator();
} else {
final ArrayDeque queue =
Iterables.getOnlyElement(nodeInfo.sinks.values()).list;
rows = Linq4j.iterableEnumerator(queue);
}
return new TransformedEnumerator(rows) {
protected Object[] transform(Row row) {
return row.getValues();
}
};
}
private void start() {
// We rely on the nodes being ordered leaves first.
for (Map.Entry entry : nodes.entrySet()) {
final NodeInfo nodeInfo = entry.getValue();
try {
nodeInfo.node.run();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
public void close() {
}
/** Not used. */
private class FooCompiler implements ScalarCompiler {
public Scalar compile(List nodes, RelDataType inputRowType) {
final RexNode node = nodes.get(0);
if (node instanceof RexCall) {
final RexCall call = (RexCall) node;
final Scalar argScalar = compile(call.getOperands(), inputRowType);
return new Scalar() {
final Object[] args = new Object[call.getOperands().size()];
public void execute(final Context context, Object[] results) {
results[0] = execute(context);
}
public Object execute(Context context) {
Comparable o0;
Comparable o1;
switch (call.getKind()) {
case LESS_THAN:
case LESS_THAN_OR_EQUAL:
case GREATER_THAN:
case GREATER_THAN_OR_EQUAL:
case EQUALS:
case NOT_EQUALS:
argScalar.execute(context, args);
o0 = (Comparable) args[0];
if (o0 == null) {
return null;
}
o1 = (Comparable) args[1];
if (o1 == null) {
return null;
}
if (o0 instanceof BigDecimal) {
if (o1 instanceof Double || o1 instanceof Float) {
o1 = new BigDecimal(((Number) o1).doubleValue());
} else {
o1 = new BigDecimal(((Number) o1).longValue());
}
}
if (o1 instanceof BigDecimal) {
if (o0 instanceof Double || o0 instanceof Float) {
o0 = new BigDecimal(((Number) o0).doubleValue());
} else {
o0 = new BigDecimal(((Number) o0).longValue());
}
}
final int c = o0.compareTo(o1);
switch (call.getKind()) {
case LESS_THAN:
return c < 0;
case LESS_THAN_OR_EQUAL:
return c <= 0;
case GREATER_THAN:
return c > 0;
case GREATER_THAN_OR_EQUAL:
return c >= 0;
case EQUALS:
return c == 0;
case NOT_EQUALS:
return c != 0;
default:
throw new AssertionError("unknown expression " + call);
}
default:
if (call.getOperator() == SqlStdOperatorTable.UPPER) {
argScalar.execute(context, args);
String s0 = (String) args[0];
if (s0 == null) {
return null;
}
return s0.toUpperCase(Locale.ROOT);
}
if (call.getOperator() == SqlStdOperatorTable.SUBSTRING) {
argScalar.execute(context, args);
String s0 = (String) args[0];
Number i1 = (Number) args[1];
Number i2 = (Number) args[2];
if (s0 == null || i1 == null || i2 == null) {
return null;
}
return s0.substring(i1.intValue() - 1,
i1.intValue() - 1 + i2.intValue());
}
throw new AssertionError("unknown expression " + call);
}
}
};
}
return new Scalar() {
public void execute(Context context, Object[] results) {
results[0] = execute(context);
}
public Object execute(Context context) {
switch (node.getKind()) {
case LITERAL:
return ((RexLiteral) node).getValueAs(Comparable.class);
case INPUT_REF:
return context.values[((RexInputRef) node).getIndex()];
default:
throw new RuntimeException("unknown expression type " + node);
}
}
};
}
}
/** Information about a node registered in the data flow graph. */
private static class NodeInfo {
final RelNode rel;
final Map sinks = new LinkedHashMap<>();
final Enumerable rowEnumerable;
Node node;
NodeInfo(RelNode rel, Enumerable rowEnumerable) {
this.rel = rel;
this.rowEnumerable = rowEnumerable;
}
}
/**
* A {@link Source} that is just backed by an {@link Enumerator}. The {@link Enumerator} is closed
* when it is finished or by calling {@link #close()}.
*/
private static class EnumeratorSource implements Source {
private final Enumerator enumerator;
EnumeratorSource(final Enumerator enumerator) {
this.enumerator = Objects.requireNonNull(enumerator);
}
@Override public Row receive() {
if (enumerator.moveNext()) {
return enumerator.current();
}
// close the enumerator once we have gone through everything
enumerator.close();
return null;
}
@Override public void close() {
enumerator.close();
}
}
/** Implementation of {@link Sink} using a {@link java.util.ArrayDeque}. */
private static class ListSink implements Sink {
final ArrayDeque list;
private ListSink(ArrayDeque list) {
this.list = list;
}
public void send(Row row) throws InterruptedException {
list.add(row);
}
public void end() throws InterruptedException {
}
@SuppressWarnings("deprecation")
@Override public void setSourceEnumerable(Enumerable enumerable)
throws InterruptedException {
// just copy over the source into the local list
final Enumerator enumerator = enumerable.enumerator();
while (enumerator.moveNext()) {
this.send(enumerator.current());
}
enumerator.close();
}
}
/** Implementation of {@link Source} using a {@link java.util.ArrayDeque}. */
private static class ListSource implements Source {
private final ArrayDeque list;
private Iterator iterator = null;
ListSource(ArrayDeque list) {
this.list = list;
}
public Row receive() {
try {
if (iterator == null) {
iterator = list.iterator();
}
return iterator.next();
} catch (NoSuchElementException e) {
iterator = null;
return null;
}
}
@Override public void close() {
// noop
}
}
/** Implementation of {@link Sink} using a {@link java.util.ArrayDeque}. */
private static class DuplicatingSink implements Sink {
private List> queues;
private DuplicatingSink(List> queues) {
this.queues = ImmutableList.copyOf(queues);
}
public void send(Row row) throws InterruptedException {
for (ArrayDeque queue : queues) {
queue.add(row);
}
}
public void end() throws InterruptedException {
}
@SuppressWarnings("deprecation")
@Override public void setSourceEnumerable(Enumerable enumerable)
throws InterruptedException {
// just copy over the source into the local list
final Enumerator enumerator = enumerable.enumerator();
while (enumerator.moveNext()) {
this.send(enumerator.current());
}
enumerator.close();
}
}
/**
* Walks over a tree of {@link org.apache.calcite.rel.RelNode} and, for each,
* creates a {@link org.apache.calcite.interpreter.Node} that can be
* executed in the interpreter.
*
* The compiler looks for methods of the form "visit(XxxRel)".
* A "visit" method must create an appropriate {@link Node} and put it into
* the {@link #node} field.
*
*
If you wish to handle more kinds of relational expressions, add extra
* "visit" methods in this or a sub-class, and they will be found and called
* via reflection.
*/
static class CompilerImpl extends RelVisitor
implements Compiler, ReflectiveVisitor {
final ScalarCompiler scalarCompiler;
private final ReflectiveVisitDispatcher dispatcher =
ReflectUtil.createDispatcher(CompilerImpl.class, RelNode.class);
protected final Interpreter interpreter;
protected RelNode rootRel;
protected RelNode rel;
protected Node node;
final Map nodes = new LinkedHashMap<>();
final Map> relInputs = new HashMap<>();
final Multimap outEdges = LinkedHashMultimap.create();
private static final String REWRITE_METHOD_NAME = "rewrite";
private static final String VISIT_METHOD_NAME = "visit";
CompilerImpl(Interpreter interpreter, RelOptCluster cluster) {
this.interpreter = interpreter;
this.scalarCompiler = new JaninoRexCompiler(cluster.getRexBuilder());
}
/** Visits the tree, starting from the root {@code p}. */
Pair> visitRoot(RelNode p) {
rootRel = p;
visit(p, 0, null);
return Pair.of(rootRel, nodes);
}
@Override public void visit(RelNode p, int ordinal, RelNode parent) {
for (;;) {
rel = null;
boolean found = dispatcher.invokeVisitor(this, p, REWRITE_METHOD_NAME);
if (!found) {
throw new AssertionError(
"interpreter: no implementation for rewrite");
}
if (rel == null) {
break;
}
if (CalcitePrepareImpl.DEBUG) {
System.out.println("Interpreter: rewrite " + p + " to " + rel);
}
p = rel;
if (parent != null) {
List inputs = relInputs.get(parent);
if (inputs == null) {
inputs = Lists.newArrayList(parent.getInputs());
relInputs.put(parent, inputs);
}
inputs.set(ordinal, p);
} else {
rootRel = p;
}
}
// rewrite children first (from left to right)
final List inputs = relInputs.get(p);
for (Ord input : Ord.zip(Util.first(inputs, p.getInputs()))) {
outEdges.put(input.e, new Edge(p, input.i));
}
if (inputs != null) {
for (int i = 0; i < inputs.size(); i++) {
RelNode input = inputs.get(i);
visit(input, i, p);
}
} else {
p.childrenAccept(this);
}
node = null;
boolean found = dispatcher.invokeVisitor(this, p, VISIT_METHOD_NAME);
if (!found) {
if (p instanceof InterpretableRel) {
InterpretableRel interpretableRel = (InterpretableRel) p;
node = interpretableRel.implement(
new InterpretableRel.InterpreterImplementor(this, null, null));
} else {
// Probably need to add a visit(XxxRel) method to CoreCompiler.
throw new AssertionError("interpreter: no implementation for "
+ p.getClass());
}
}
final NodeInfo nodeInfo = nodes.get(p);
assert nodeInfo != null;
nodeInfo.node = node;
if (inputs != null) {
for (int i = 0; i < inputs.size(); i++) {
final RelNode input = inputs.get(i);
visit(input, i, p);
}
}
}
/** Fallback rewrite method.
*
* Overriding methods (each with a different sub-class of {@link RelNode}
* as its argument type) sets the {@link #rel} field if intends to
* rewrite. */
public void rewrite(RelNode r) {
}
public Scalar compile(List nodes, RelDataType inputRowType) {
if (inputRowType == null) {
inputRowType = interpreter.dataContext.getTypeFactory().builder()
.build();
}
return scalarCompiler.compile(nodes, inputRowType);
}
public RelDataType combinedRowType(List inputs) {
final RelDataTypeFactory.Builder builder =
interpreter.dataContext.getTypeFactory().builder();
for (RelNode input : inputs) {
builder.addAll(input.getRowType().getFieldList());
}
return builder.build();
}
public Source source(RelNode rel, int ordinal) {
final RelNode input = getInput(rel, ordinal);
final Edge edge = new Edge(rel, ordinal);
final Collection edges = outEdges.get(input);
final NodeInfo nodeInfo = nodes.get(input);
if (nodeInfo == null) {
throw new AssertionError("should be registered: " + rel);
}
if (nodeInfo.rowEnumerable != null) {
return new EnumeratorSource(nodeInfo.rowEnumerable.enumerator());
}
assert nodeInfo.sinks.size() == edges.size();
final ListSink sink = nodeInfo.sinks.get(edge);
if (sink != null) {
return new ListSource(sink.list);
}
throw new IllegalStateException(
"Got a sink " + sink + " to which there is no match source type!");
}
private RelNode getInput(RelNode rel, int ordinal) {
final List inputs = relInputs.get(rel);
if (inputs != null) {
return inputs.get(ordinal);
}
return rel.getInput(ordinal);
}
public Sink sink(RelNode rel) {
final Collection edges = outEdges.get(rel);
final Collection edges2 = edges.isEmpty()
? ImmutableList.of(new Edge(null, 0))
: edges;
NodeInfo nodeInfo = nodes.get(rel);
if (nodeInfo == null) {
nodeInfo = new NodeInfo(rel, null);
nodes.put(rel, nodeInfo);
for (Edge edge : edges2) {
nodeInfo.sinks.put(edge, new ListSink(new ArrayDeque()));
}
}
if (edges.size() == 1) {
return Iterables.getOnlyElement(nodeInfo.sinks.values());
} else {
final List> queues = new ArrayList<>();
for (ListSink sink : nodeInfo.sinks.values()) {
queues.add(sink.list);
}
return new DuplicatingSink(queues);
}
}
public void enumerable(RelNode rel, Enumerable rowEnumerable) {
NodeInfo nodeInfo = new NodeInfo(rel, rowEnumerable);
nodes.put(rel, nodeInfo);
}
public Context createContext() {
return new Context(getDataContext());
}
public DataContext getDataContext() {
return interpreter.dataContext;
}
}
/** Edge between a {@link RelNode} and one of its inputs. */
static class Edge extends Pair {
Edge(RelNode parent, int ordinal) {
super(parent, ordinal);
}
}
/** Converts a list of expressions to a scalar that can compute their
* values. */
interface ScalarCompiler {
Scalar compile(List nodes, RelDataType inputRowType);
}
}
// End Interpreter.java